11 Matching Results

Search Results

Advanced search parameters have been applied.

Evaluation of the electrorefining technique for the processing of radioactive scrap metals

Description: This report presents the results of a literature study performed to identify applications of the electrorefining technique to the decontamination of radioactively-contaminated scrap metal (RSM). Upon the completion of the literature search and the review of numerous references, it was concluded that there were applications of this technique that were appropriate for the decontamination of some types of RSM, especially when the desired product is a pure elemental metal of high purity. It was also concluded that this technique was not well-suited for the decontamination of RSM stainless steels and other alloys, when it was desired that the metallurgical characteristics of the alloy be present in the decontaminated product.
Date: October 1, 1993
Creator: Kessinger, G.F.
Partner: UNT Libraries Government Documents Department

Decontamination of FAST (CPP-666) fuel storage area stainless steel fuel storage racks

Description: The purpose of this report was to identify and evaluate alternatives for the decontamination of the RSM stainless steel that will be removed from the Idaho Chemical Processing plant (ICPP) fuel storage area (FSA) located in the FAST (CPP-666) building, and to recommend decontamination alternatives for treating this material. Upon the completion of a literature search, the review of the pertinent literature, and based on the review of a variety of chemical, mechanical, and compound (both chemical and mechanical) decontamination techniques, the preliminary results of analyses of FSA critically barrier contaminants, and the data collected during the FSA Reracking project, it was concluded that decontamination and beneficial recycle of the FSA stainless steel produced is technically feasible and likely to be cost effective as compared to burying the material at the RWMC. It is recommended that an organic acid, or commercial product containing an organic acid, be used to decontaminate the FSA stainless steel; however, it is also recommended that other surface decontamination methods be tested in the event that this method proves unsuitable. Among the techniques that should be investigated are mechanical techniques (CO{sub 2} pellet blasting and ultra-high pressure water blasting) and chemical techniques that are compatible with present ICPP waste streams.
Date: October 1, 1993
Creator: Kessinger, G.F.
Partner: UNT Libraries Government Documents Department

LITERATURE REVIEW: REDUCTION OF NP(V) TO NP (IV)-ALTERNATIVES TO FERROUS SULFAMATE

Description: The baseline approach to control of Np oxidation in UREX and PUREX separation processes is the reduction of Np(V) and Np(VI) to Np(IV) using ferrous sulfamate. Use of this reagent results in increased sulfur and iron concentrations in the liquid waste streams from the process. Presence of these two elements, especially sulfur, increases the complexity of the development of wasteforms for immobilizing these effluents. Investigations are underway to identify reductants that eliminate sulfur and iron from the Np reduction process. While there are a variety of chemical reductants that will reduce Np to Np(IV) in nitric acid media, the reaction rates for most are so slow that the reductants are not be feasible for use in an operating plant process. In an attempt to identify additional alternatives to ferrous sulfamate, a literature search and review was performed. Based on the results of the literature review, it is concluded that photochemical and catalytic processes should also be investigated to test the utility of these two approaches. The catalytic process could be investigated for use in conjunction with chemical oxidants to speed the reaction rates for reductants that react slowly, but would otherwise be appropriate replacements for ferrous sulfamate. The photochemical approach, which has received little attention during the past few decades, also shows promise, especially the photocatalytic approach that includes a catalyst, such as Pt supported on SiC, which can be used in tandem with an oxidant, for Np reduction.
Date: September 28, 2009
Creator: Kessinger, G.; Kyser, E. & Almond, P.
Partner: UNT Libraries Government Documents Department

EVALUATION OF PLUTONIUM OXIDE DESTRUCTIVE CHEMICAL ANALYSES FOR VALIDITY OF ORIGINAL 3013 CONTAINER BINNING

Description: The surveillance program for 3013 containers is based, in part, on the separation of containers into various bins related to potential container failure mechanisms. The containers are assigned to bins based on moisture content and pre-storage estimates of content chemistry. While moisture content is measured during the packaging of each container, chemistry estimates are made by using a combination of process knowledge, packaging data and prompt gamma analyses to establish the moisture and chloride/fluoride content of the materials. Packages with high moisture and chloride/fluoride contents receive more detailed surveillances than packages with less chloride/fluoride and/or moisture. Moisture verification measurements and chemical analyses performed during the surveillance program provided an opportunity to validate the binning process. Validation results demonstrated that the binning effort was generally successful in placing the containers in the appropriate bin for surveillance and analysis.
Date: February 1, 2010
Creator: Mcclard, J. & Kessinger, G.
Partner: UNT Libraries Government Documents Department

DISSOLUTION OF ZIRCALOY 2 CLAD UO2 COMMERCIAL REACTOR FUEL

Description: The primary goal of this investigation was to evaluate the effectiveness of the chop-leach process, with nitric acid solvent, to produce a nominally 300 g/L [U] and 1 M [H{sup +}] product solution. The results of this study show that this processing technique is appropriate for applications in which a low free acid and moderately high U content are desired. The 7.75 L of product solution, which was over 450 g/L in U, was successfully diluted to produce about 13 L of solvent extraction feed that was 302 g/L in U with a [H{sup +}] in the range 0.8-1.2 M. A secondary goal was to test the effectiveness of this treatment for the removal of actinides from Zircaloy cladding to produce a low-level radioactive waste (LLW) cladding product. Analysis of the cladding shows that actinides are present in the cladding at a concentration of about 5000 {eta}Ci/g, which is about 50 times greater than the acceptable transuranium element limit in low level radioactive waste. It appears that the concentration of nitric acid used for this dissolution study (initial concentration 4 M, with 10 M added as the dissolution proceeded) was inadequate to completely digest the UO{sub 2} present in the spent fuel. The mass of insoluble material collected from the initial treatments with nitric acid, 340 g, was much higher than expected, and analysis of this insoluble residue showed that it contained at least 200 g U.
Date: August 7, 2009
Creator: Kessinger, G. & Thompson, M.
Partner: UNT Libraries Government Documents Department

THE HIGH TEMPERATURE CHEMICAL REACTIVITY OF LI2O

Description: The ultimate purpose of this study was to investigate the use of a Li-Ca mixture for direct reduction of actinide oxides to actinide metals at temperatures below 1500 C. For such a process to be successful, the products of the reduction reaction, actinide metals, Li{sub 2}O, and CaO, must all be liquid at the reaction temperature so the resulting actinide metal can coalesce and be recovered as a monolith. Since the established melting temperature of Li{sub 2}O is in the range 1427-1700 C and the melting temperature of CaO is 2654 C, the Li{sub 2}O-CaO (lithium oxidecalcium oxide) pseudo-binary system was investigated in an attempt to identify the presence of low-melting eutectic compositions. The results of our investigation indicate that there is no evidence of ternary Li-Ca-O phases or solutions melting below 1200 C. In the 1200-1500 C range utilizing MgO crucibles, there is some evidence for the formation of a ternary phase; however, it was not possible to determine the phase composition. The results of experiments performed with ZrO{sub 2} crucibles in the same temperature range did not show the formation of the possible ternary phase seen in the earlier experiment involving MgO crucibles, so it was not possible to confirm the possibility that a ternary Li-Ca-O or Li-Mg-O phase was formed. It appears that the Li{sub 2}O-CaO materials reacted, to some extent, with all of the container materials, alumina (Al{sub 2}O{sub 3}), magnesia (MgO), zirconia (ZrO{sub 2}), and 95% Pt-5% Au; however, to clarify the situation additional experiments are required. In addition to the primary purpose of this study, the results of this investigation led to the conclusions that: (1) The melting temperature of Li{sub 2}O may be as low as 1250 C, which is considerably lower than the previously published values in the range 1427-1700 C; (2) ...
Date: November 13, 2009
Creator: Kessinger, G. & Missimer, D.
Partner: UNT Libraries Government Documents Department

MOISTURE AND SURFACE AREA MEASUREMENTS OF PLUTONIUM-BEARING OXIDES

Description: To ensure safe storage, plutonium-bearing oxides are stabilized at 950 C for at least two hours in an oxidizing atmosphere. Stabilization conditions are expected to decompose organic impurities, convert metals to oxides, and result in moisture content below 0.5 wt%. During stabilization, the specific surface area is reduced, which minimizes readsorption of water onto the oxide surface. Plutonium oxides stabilized according to these criteria were sampled and analyzed to determine moisture content and surface area. In addition, samples were leached in water to identify water-soluble chloride impurity content. Results of these analyses for seven samples showed that the stabilization process produced low moisture materials (< 0.2 wt %) with low surface area ({le} 1 m{sup 2}/g). For relatively pure materials, the amount of water per unit surface area corresponded to 1.5 to 3.5 molecular layers of water. For materials with chloride content > 360 ppm, the calculated amount of water per unit surface area increased with chloride content, indicating hydration of hygroscopic salts present in the impure PuO{sub 2}-containing materials. The low moisture, low surface area materials in this study did not generate detectable hydrogen during storage of four or more years.
Date: September 28, 2009
Creator: Crowder, M.; Duffey, J.; Livingston, R.; Scogin, J.; Kessinger, G. & Almond, P.
Partner: UNT Libraries Government Documents Department

GAS ANALYSES FROM HEADSPACE OF PLUTONIUM-BEARING MATERIALS CONTAINERS

Description: The Savannah River National Laboratory (SRNL) 3013 destructive examination program performs surveillances on 3013 containers originating from multiple sites across the DOE complex. The bases for the packaging, storage, and surveillance activities are derived from the Department of Energy's 3013 Standard (DOE-STD-3013-2004). During destructive examination, headspace gas samples are obtained from the 3013 inner container and the annulus between the outer and inner containers. To characterize gas species, the samples are analyzed by gas chromatography (GC), direct-inlet mass spectrometry (DIMS), and Fourier-transform infrared spectroscopy (FTIR). The GC results, as well as other parameters, are utilized as input into the gas evaluation software tool (GEST) program for computation of pre-puncture gas compositions and pressures. Over 30 containers from the Hanford Site and the Rocky Flats Environmental Technology Site (RFETS) have been examined in the first three years of the surveillance program. Several containers were shown to have appreciable hydrogen content (some greater than 30 mol %), yet little or no oxygen was detected in any of the containers, including those exhibiting high hydrogen concentrations. Characteristics including moisture content, surface area, and material composition, along with the headspace gas composition, are utilized in an attempt to explain the chemical behavior of the packaged materials.
Date: February 1, 2010
Creator: Almond, P.; Livingston, R.; Traver, L.; Arnold, M.; Bridges, N.; Kessinger, G. et al.
Partner: UNT Libraries Government Documents Department

Industry-identified combustion research needs: Special study

Description: This report discusses the development and demonstration of innovative combustion technologies that improve energy conservation and environmental practices in the US industrial sector. The report includes recommendations by industry on R&D needed to resolve current combustion-related problems. Both fundamental and applied R&D needs are presented. The report assesses combustion needs and suggests research ideas for seven major industries, which consume about 78% of all energy used by industry. Included are the glass, pulp and paper, refinery, steel, metal casting, chemicals, and aluminum industries. Information has been collected from manufacturers, industrial operators, trade organizations, and various funding organizations and has been supplemented with expertise at the Idaho National Engineering Laboratory to develop a list of suggested research and development needed for each of the seven industries.
Date: November 1, 1995
Creator: Keller, J.G.; Soelberg, N.R. & Kessinger, G.F.
Partner: UNT Libraries Government Documents Department

MATERIAL PROPERTIES OF PLUTONIUM-BEARING OXIDES STORED IN STAINLESS STEEL CONTAINERS

Description: The destructive examination (DE) of 3013 containers after storage is part of the Surveillance and Monitoring Program based on the Department of Energy's standard for long-term storage of Pu (DOE-STD-3013). The stored, Pu-bearing materials may contain alkali halide contamination that varies from trace amounts of salt to about 50 weight percent, with smaller fractions of other compounds and oxides. These materials were characterized prior to packaging, and surveillance characterizations are conducted to determine the behavior of the materials during long term storage. The surveillance characterization results are generally in agreement with the pre-surveillance data. The predominant phases identified by X-ray diffraction are in agreement with the expected phase assemblages of the as-received materials. The measured densities are in reasonable agreement with the expected densities of materials containing the fraction of salts and actinide oxide specified by the pre-surveillance data. The radiochemical results are generally in good agreement with the pre-surveillance data for mixtures containing 'weapons grade' Pu (nominally 94% {sup 239}Pu and 6% {sup 240}Pu); however, the ICP-MS results from the present investigation generally produce lower concentrations of Pu than the pre-surveillance analyses. For mixtures containing 'fuel grade' Pu (nominally 81-93% {sup 239}Pu and 7-19% {sup 240}Pu), the ICP-MS results from the present investigation appear to be in better agreement with the pre-surveillance data than the radiochemistry results.
Date: February 1, 2010
Creator: Kessinger, G.; Almond, P.; Bridges, N.; Bronikowski, M.; Crowder, M.; Duffey, J. et al.
Partner: UNT Libraries Government Documents Department